Turbine blading



July 16, 1929. SCHMIDT 1,720,695

TURBINE BLADING Filed Dec. 15 1927 WITNESSES INVENVTOR 5. ll-fischmidl' I BY mam ATTORNEY Fatentecl July 16, 1929.

' UNITED STATES PATENT OFFICE.

HENRY F. SCHMIDT, OF LANSDOWNE, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE H ELECTRIC 8t MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

TURBINE BLADING.

Application filed December 15, 1927. Serial No. 240,224.

My invention relates to elastic fluid turbines, and more particularly to turbines having impulse wheels of smaller sizes, and 1t has for an object, to improve the construction of apparatus of this character.

Another object is to simplify the manufacture and the assembling of the blading for apparatus of the type described.

A further object is to provide a blade fastoning of the De Laval type which shall be relatively inexpensive to produce.

Apparatus embodying the features of my invention is shown in the accompanying drawings, forming a part of this specification,

and wherein:

Fig. 1 is a section through a bar of blade stock;

Fig. 2 is an end view taken from the tip end of a turbine blade;

Fig. 3 is an elevation of the blade shown in Fig. 2;

Fig. 4 is an end elevation of a portion of a turbine rotor, with the blades removed; and,

Fig. 5 is a longitudinal section through a turbine rotor showing the manner in which the blades are secured therein.

In Fig. 1, I shoW a section of stock 10, from which my blades may be made, while in Figs. 2 and 3 I show the same section of stock after it has been cut to form the blade portion 11, the root portion 12 and the tail piece 13, which joins the blade portion and the root portion of the blade. From Fig. 2, it will be apparent that blade portion 11 is bent to give it the desired curvature, while the root portion 12, preferably, retains the shape of the original stock section 10. This leaves the root 12 with wings 14, which extend laterally beyond the edges of the blade 11. Preferably, the back of the root is scraped off, or otherwise fiattened, as indicated 'at 12' in Fig. 2, so that the root may be inserted in a straight slot in a rotor, but of course, if desired, the root may be left curved as shown in Fig. 1, in which case curved slots would be provided in the rotor.

In Fig. 4, I show a turbine wheel 16 in which radial slots 17 extend inwardly from the periphery thereof to meet the holes 18, the latter forming an enlargement of each slot at the inner, or closed end thereof. The parts of the blades and the rotor 16 are so constructed and arranged that the tail portions 13 of the blades fit the radial slots 17,

and the wings 14 extend loosely through the holes 18.

After the root portion of a blade has been inserted in the rotor in the manner just described, the wings 14 of the root portion are upset toward each other so as to substantially fill the round hole at the bottom of the slot and thus, to securely anchor the blade therein. In this connection, it will be observed that those portions of the holes 18, which receive the tips of the wings 14, serve as guides for the plungers 19, or the like, which upset the wings. The radial slots 17 also serve to stiffen the blades.

lVhile I have shown the wings 14 as being arranged to initially protrude slightly from the holes 18 on both sides of the rotor, it will be obvious to one skilled in this art that these wings may be arranged to extend greater or less amounts on either side of the rotor, or they may be arranged so as to be, initially, entirely within the holes 18, as the purpose of the wings is to provide suflicient surplus metal to form a suitable fastening, when upset.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and I desire, therefore, thatonly such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is 1. The combination with a turbine wheel having its periphery cut radially by transversely extending slots which have their inner ends enlarged, of a row of blades provided with root portions fitting the respective slots, each of said root portions comprising a shank extending to the bottom of the slot and fitting the slot from the periphery of the wheel to the enlarged portion, wings on the shank extending laterally thereof and lengthwise of the enlarged portion of the slot, said wings being upset to fill the enlarged portion of the slot and thereby retain the blade in the wheel.

2. The combination with a turbine wheel having transverse retaining slots extending substantially radially inwardly to enlarged portions at the respective closed ends thereof, the radial portions of said slots being of substantially uniform thickness, of a row of blades provided with root portions fitting the respective slots, each of said root portions comprising a shank extending through the radial portion of its respective slot to the bottom of the enlarged portion at the closed end thereof, said shank fitting the radial portion of the slot and being of substantially the same thickness throughout, and Wings on the shank 

